I own a 79 305 Camaro.  ive heard from some that increasing compression via head milling is not worth it if you dont redline your car and kills bottom end torque, is this true?  I want to get the C.R. up to around 9.5:1 (stock its around a high 7, low 8:1), and fit it with a cam with a 480 lift.  If milling is recommended, anyone know in the New York area where their is a cheap place to get heads milled?

Thanks  

umm, how should i put this, id trash the 305 and buy a junkyard 350 and youd have more power than that 305 with the cam and angle milling of the heads

don't even bother with a 305.  They're a #### engine compared to a 350.  If memory serves those 305's made like 170 horse.  Chuck the motor out, get a block and start building.  You'll be a lot happier in the end.   

your engine came off the floor with about 145 bhp.  The exhaust system is very restrictive.  The heads are the worst ones chevy ever produced.  The only way you could possibly produce any decent power is if you swap the heads.  It would be much more easy if you went to the 350.  For the price of a camshaft and manifold, you could grab a running 350 out of a junkyard.  

you can take that 305 and buy a boat and tie it to a chain   presto a anchor.  

now that you've gotten replies,here is an answer:

milling the heads will increase the compression ratio.if all else stays the same,(head gasket thickness).no it won't kill your low end tq. it will actually increase tq. everywhere.

milling these heads is not worth it because they are so thin to start with.once milled,they will warp as soon as you heat em up.

i agree your best bet is a 350.

a stock,good 350 from a bone yard will make more tq./hp than your 305+lends itself well to future mods & is very durable.

hope this helps.

buzzin half duzzin  

What a lot of people apparently don't know (and hot rod magazine proved this a few months ago) is that the chevy 305 small-block has the longest stroke of any small-block ever produced, and one hot rod subscriber took a good shape 305 , and with a little bit of elbow grease and not much cash made 394 horses on the engine dyno with the stock crank (worked over with a body sander of all things) and some 350 heads i believe. He also made over 350 ft. lbs. of torque. The 305 is not a "boat anchor". You will only hear that from people who are, sorry to say, undereducated on engines (or Ford guys, same thing) or people that are too lazy to go out and put the work and time into that humble little motor to make it the bad ass bowtie powerhouse that it can be!!!!!  

mongo58:
What a lot of people apparently don't know (and hot rod magazine proved this a few months ago) is that the chevy 305 small-block has the longest stroke of any small-block ever produced, and one hot rod subscriber took a good shape 305 , and with a little bit of elbow grease and not much cash made 394 horses on the engine dyno with the stock crank (worked over with a body sander of all things) and some 350 heads i believe. He also made over 350 ft. lbs. of torque. The 305 is not a "boat anchor". You will only hear that from people who are, sorry to say, undereducated on engines (or Ford guys, same thing) or people that are too lazy to go out and put the work and time into that humble little motor to make it the bad ass bowtie powerhouse that it can be!!!!!

Agreed, Hot Rodders believe the cheapest way to build power is to go with a 350. I have bought plenty of books and read up on various tuning methods, the gains and sacrifices from tuning, and problem areas with SBC engines. You want power on the cheap, right? I can tell you some gudlines to build a decently powered 305, that gets good gas mileage to boot. The number one question, IS THIS A STREETCAR? or a RACECAR?305's should be built for street use, they have very little potential at a dragstrip. Your best bet to build up CR to 9.5: 1 is to buy a set of heads with this casting number 14014416. They have 58cc combustion chamber 165cc intake runners, 56cc exhuast runners, 1.84 intake and 1.5 exhaust valves respectively. This will boost compression well over 9 : 1 and will increase your flow over your 415 cast heads with their 1.72 intake, and 1.30 exhaust valves, and the bigger 64 cc chaambers. I have 415 cast heads on my 267. DO NOT mill either set if heads. Both are considerably thin cast and are prone to cracking. Next go with a allow duration, near stock or slightly above camshaft, that has a high lift, under 500". A good dual plane manifold matched for you cam will not only improve flow and shift your power curve into the mid-high RPM range, it'll maintain good vacuum at idle and help the engine remain streetable. Go with a decent set of 1 5/8 headers and a dual exhaust with 2 1/2 inch pipes, probably some flowmasters to silcence the part throttle. Have the heads 'pocket ported' this is a porting process for street ingine, that will improve fuel atomization, flow, and efficiency. Make sure to get a 3 angle valve job as well to maximze flow though your heads.

You may not get 394 HP, but you'll see well over 300, probably closer to 315 or 320. Should occur near 5000 RPM too. That is better than the 145 HP at 3800 RPM youhave stock. Get an edelbrock 1406 600 cfm 4 barrel performer series carb as well. They are very easy to calibrate and are a very efficient crab, if you don't mash the gaspedal to the floor. I recently drove to Pittsburgh from Warren, OH. A 187 mile trip didn't cost me more than 6.5 gallons of fuel, with my 3 speed THM-350 and no-lockup converter. It avgs out to aroun 26-27 MPG.

Your heads will cost you alot to machine/refurbish, but it'll payoff in the long run. On top of that, if you can find a boneyard 350, you'll have to pay for an engine that you may have to later rebuild after modification. You'll pay a core charge if you do not return you 305 too. So not only will you have a possibility of a blown engine, you may not have a spare to replace it.

Alot of people are starting to build 305's. I have seen a few in my time. I'm building a 267, and getting ready to build a 283.  

400 horsepower out of a 305 with non-vortec OE cast-iron heads. I don't believe you.